[Bug] Switching podcast quality preset leads to distorted recording

[Vekhir]

Describe the bug

Starting another recording after changing the quality preset leads to incorrect video.

To Reproduce

1. Start recording on any setting, e.g. "Medium"
2. Stop recording. This video is fine.
3. Change recording preset to another setting, e.g. "Full"
4. Stop recording. The video file has the correct dimensions, but large parts are black (or only partially visible if going from Medium to Small).

Expected behavior

The video should always show the entire the display area, scaled to the video resolution.

Actual behavior

The video only shows part of the display area or pads it with black.

Screenshots

First recording with Medium:

Second recording with Full:

Third recording with Small:

Additional resources

Recording_bug.pdf

Context

• reproducibility : systematic
• OpenBoard version :
  • bug happens with : 1.7.3, dev
  • didn't check : before 1.7.3
• OS :
  • bug happens with : Linux
  • didn't check : Windows macOS
• Installation source : Arch Linux AUR package

Additional context

System:
OS: Arch Linux
Kernel: Linux 6.13.2-arch1-1
Qt: 6.8.2-2
FFmpeg: 2:7.1-6
number and resolution of monitors : 1x1920x1080

I found this bug while trying to increase the recording fps. It is reproducible in the stable version, but only affects subsequent recordings with different resolutions. Restarting OpenBoard and selecting a different preset works fine and serves as a workaround to this bug - if one is aware of that.